1. Technical Field
The present invention relates to a door for closing an opening in a wall, preferably a wall which separates two different temperature zones from one another, in particular one belonging to a cold store, having a door leaf, which can be moved in front of the wall opening, and having a heater for heating at least one door component. The invention also relates to a door leaf for such a door. The invention additionally relates to a winding-up shaft for winding up a door leaf or part of the leaf of a rolling door for closing a wall opening, wherein the winding-up shaft, for winding up at least one web of the door leaf, has a suitable winding surface.
2. Prior Art
In particular in conjunction with the use in cold stores, it is known to heat components of doors. The heating here serves predominantly to avoid the formation of ice on various door components. Such ice formation usually results in malfunctioning of the door.
German patent number DE 196 25 215 C2 discloses a rolling door in which warm air coming from a heating device arranged in the upper region of the door flows through side parts of the rolling door, in which the lateral edges of the rolling-door leaf are guided. In addition, lower regions of the side parts contain openings through which the warm air can penetrate laterally into the rolling-door leaf when the rolling door is closed. The rolling-door leaf is formed from webs which enclose an interspace into which the warm air can penetrate. The warm air can rise upwards within this interspace and also heat the rolling-door leaf in the process.
One disadvantage with this solution is that the warm air, as it passes through the side parts, has already lost heat energy as soon as it reaches the interspace of the rolling-door leaf. Most of the rolling-door leaf, therefore, is heated possibly only to an insufficient extent and is kept ice-free only to an insufficient extent. In addition, it is also the case that, with the rolling door open, the warm air escapes from the openings and is then discharged ineffectively to the surroundings.
A fundamental disadvantage of rolling doors with flexible webs is that the operation of winding up these webs onto the winding-up shaft gives rise to unbalances. Despite the usually rotationally symmetrical winding surface of the winding-up shaft, the masses of the rotating overall structure made of the winding-up shaft and already partially wound-up rolling-door web are no longer distributed in a rotationally symmetrical manner in relation to the axis of rotation of the shaft. The already wound-up portion of the rolling-door web causes this non-symmetrical mass distribution.